class: center middle main-title section-title-3 # In-person<br>session 9 .class-info[ **March 9, 2023** .light[PMAP 8521: Program evaluation<br> Andrew Young School of Policy Studies ] ] --- name: outline class: title title-inv-8 # Plan for today -- .box-3.medium[General questions] -- .box-7.medium[Final project] -- .box-1.medium[Simple diff-in-diff] -- .box-6.medium[Two-way fixed effects] -- .box-2.medium[Markdown fun] --- layout: false name: general-questions class: center middle section-title section-title-3 animated fadeIn # General questions --- class: middle .box-3.large[Should we control for variables<br>to close as many backdoors as<br>possible in our diff-in-diff model?] --- class: title title-3 # Design-based identification .box-inv-3[Use a special situation to isolate arrow] .pull-left[ .box-3[RCTs] .box-inv-3.small[Use randomization<br>to remove confounding] .center[ <figure> <img src="05-slides_files/figure-html/experimental-dag-1.png" alt="RCT DAG" title="RCT DAG" width="60%"> </figure> ] ] -- .pull-right[ .box-3[Difference-in-differences] .box-inv-3.small[Use before/after & treatment/control<br>differences to remove confounding] .center[ <figure> <img src="08-slides_files/figure-html/min-wage-dag-1.png" alt="Diff-in-diff DAG" title="Diff-in-diff DAG" width="90%"> </figure> ] ] --- layout: true class: middle --- .box-3.large[How does moving time back<br>let us check for parallel trends?] --- .center[ <figure> <img src="img/08-class/mm-fig-5-4.png" alt="Mastering Metrics Figure 5.4" title="Mastering Metrics Figure 5.4" width="65%"> </figure> ] --- .box-3.large[Can you conduct diff-in-diff<br>with a binary outcome?] ??? - <https://www.andrewheiss.com/blog/2021/11/08/beta-regression-guide/#1-linear-probability-models> - <https://bayesf22-notebook.classes.andrewheiss.com/bayes-rules/13-chapter.html#prelude-ii-how-to-interpret-logistic-regression-coefficients> --- layout: false name: final-project class: center middle section-title section-title-7 animated fadeIn # Final project --- class: middle .box-7.large[Tell us more about<br>the final project!] --- layout: false name: diff-in-diff class: center middle section-title section-title-1 animated fadeIn # Simple diff-in-diff --- layout: true class: middle --- .box-1.large[Minimum legal drinking age] --- .box-inv-1.medium[MLDA reduction] .box-1.medium[Two states: Alabama vs. Arkansas] `$$\begin{aligned} \text{Mortality}\ =&\ \beta_0 + \beta_1\ \text{Alabama} + \beta_2\ \text{After 1975}\ + \\ &\ \beta_3\ (\text{Alabama} \times \text{After 1975}) \end{aligned}$$` --- layout: false name: twfe class: center middle section-title section-title-6 animated fadeIn # Two-way fixed effects<br>(TWFE) --- layout: true class: middle --- .box-6.medium[Two states: Alabama vs. Arkansas] `$$\begin{aligned} \text{Mortality}\ =&\ \beta_0 + \beta_1\ \text{Alabama} + \beta_2\ \text{After 1975}\ + \\ &\ \beta_3\ (\text{Alabama} \times \text{After 1975}) \end{aligned}$$` --- .box-6.medium[All states: `Treatment == 1`<br>if legal for 18-20-year-olds to drink] `$$\text{Mortality}\ =\ \beta_0 + \beta_1\ \text{Treatment} + \beta_2\ \text{State} + \beta_3\ \text{Year}$$` --- `$$\begin{aligned} \text{Mortality}\ =&\ \beta_0 + \beta_1\ \text{Alabama} + \beta_2\ \text{After 1975}\ + \\ &\ \color{red}{\beta_3}\ (\text{Alabama} \times \text{After 1975}) \end{aligned}$$` .center[vs.] `$$\text{Mortality}\ =\ \beta_0 + \color{red}{\beta_1}\ \text{Treatment} + \beta_2\ \text{State} + \beta_3\ \text{Year}$$` --- .center[ <figure> <img src="img/08-class/mm-tbl-5-2.png" alt="Mastering Metrics Table 5.2" title="Mastering Metrics Table 5.2" width="55%"> </figure> ] --- .box-6.large[What about this<br>staggered treatment stuff?] .box-inv-6[[See this](https://www.andrewheiss.com/blog/2021/08/25/twfe-diagnostics/)] ??? This is good for ethical reasons! Blog post --- .box-6.large[What are random effects?] .box-inv-6[[See this](https://www.andrewheiss.com/blog/2021/12/01/multilevel-models-panel-data-guide/)] --- layout: false name: quarto class: center middle section-title section-title-2 animated fadeIn # Bonus fun with<br>R Markdown and Quarto --- layout: true class: middle --- .box-2.large.sp-after[Documents] .box-2.large[Websites]